<template>
  <div>
    <div class="goods">
      <div class="menu-wrapper">
        <ul v-if="goods" >
          <!--current-->
          <li class="menu-item " v-for="(good,index) in goods"
              :key="index"
              :class="{current:index === currentIndex}"
              @click="clickItem(index)"
          >
            <span class="text bottom-border-1px">
              <img class="icon" :src="good.icon" v-if="good.icon">
              {{good.name}}
            </span>
          </li>
        </ul>
      </div>
      <div class="foods-wrapper" >
        <ul ref="foodsUl">
          <li class="food-list-hook"
              v-for="(good,index) in goods"
              :key="index"

          >
            <h1 class="title">{{good.name}}</h1>
            <ul>
              <li class="food-item bottom-border-1px"
                  v-for="(item,index) in good.foods"
                  :key="index"
                  @click="showFood(item)"
              >
                <div class="icon">
                  <img width="57" height="57" v-lazy="item.icon">
                </div>
                <div class="content">
                  <h2 class="name">{{item.name}}</h2>
                  <p class="desc"></p>
                  <div class="extra">
                    <span class="count">月售{{item.sellCount}}份</span>
                    <span>好评率{{item.rating}}%</span>
                  </div>
                  <div class="price">
                    <span class="now">￥{{item.price}}</span>
                    <span class="old" v-if="item.oldPrice">{{item.oldPrice}}￥</span>
                  </div>
                  <div class="cartcontrol-wrapper">
                    <cart :food="item"></cart>
                  </div>
                </div>
              </li>
            </ul>
          </li>
        </ul>
      </div>
      <ShopCart></ShopCart>
    </div>
    <food :food="food" ref="food"></food>

  </div>
</template>

<script>
  import {mapGetters} from 'vuex';
  import Cart from '../Cart/Cart';
  import Food from '../../Food/Food'
  import ShopCart from '../ShopCart/ShopCart'
  import Bscroll from 'better-scroll';

    export default {
      name: "goods",
      data(){
        return{
          scrollY:0,
          tops:[],
          food:{}
        }
      },
      components:{
        Cart,
        Food,
        ShopCart
      },
      computed:{
        ...mapGetters(['goods']),
        //计算得到当前分类的下标
        currentIndex(){
           // 根据条件计算值
          const {scrollY,tops} = this;

          let index = tops.findIndex((top,i)=> {
              return scrollY >=top && scrollY< tops[i+1]
          });
          return index
        }
      },
      mounted(){
        this.$store.dispatch('getShopGoods',()=>{
          this.$nextTick(()=>{
            this._initScroll();
            this._scollTop()
          })
        });
      },

      methods:{
       _initScroll(){
         this.scroll = new Bscroll('.menu-wrapper',{
           click:true
         });
         this.foodsScroll = new Bscroll('.foods-wrapper', {
           probeType: 2,  // 因为惯性滑动不会触发
           click: true
         });
         // better-scroll 通过on来绑定事件监听
         this.foodsScroll.on('scroll',({x,y})=>{
           this.scrollY=Math.abs(y);
         });
         // 结束
         this.foodsScroll.on('scrollEnd',({x,y})=>{
           this.scrollY=Math.abs(y);
         })
       },
        _scollTop(){
          // 找到所有的分类的li
          // 初始化tops
          let tops = [];
          let top = 0;
          tops.push(top);
          let list = this.$refs.foodsUl.children;
          Array.prototype.slice.call(list).forEach((li)=>{
            top+=li.clientHeight;
            tops.push(top)
          });
          this.tops = tops;

        },
        clickItem(index){
         let sY = this.tops[index];
         this.scrollY =sY
          this.foodsScroll.scrollTo(0,-sY,500)
        },
        showFood(food){
         console.log(food)
         this.food = food;
         this.$refs.food.toggleShow()
        }
      }
    }
</script>

<style lang="stylus" rel="stylesheet/stylus">
  @import "../../../common/stylus/mixins.styl"
  .goods
    display: flex
    position: absolute
    top: 195px
    bottom: 46px
    width: 100%
    background: #fff;
    overflow: hidden
    .menu-wrapper
      flex: 0 0 80px
      width: 80px
      background: #f3f5f7
      .menu-item
        display: table
        height: 54px
        width: 56px
        padding: 0 12px
        line-height: 14px
        &.current
          position: relative
          z-index: 10
          margin-top: -1px
          background: #fff
          color: $green
          font-weight: 700
          .text
            border-none()
        .icon
          display: inline-block
          vertical-align: top
          width: 12px
          height: 12px
          margin-right: 2px
          background-size: 12px 12px
          background-repeat: no-repeat
        .text
          display: table-cell
          width: 56px
          vertical-align: middle
          bottom-border-1px(rgba(7, 17, 27, 0.1))
          font-size: 12px
    .foods-wrapper
      flex: 1
      .title
        padding-left: 14px
        height: 26px
        line-height: 26px
        border-left: 2px solid #d9dde1
        font-size: 12px
        color: rgb(147, 153, 159)
        background: #f3f5f7
      .food-item
        display: flex
        margin: 18px
        padding-bottom: 18px
        bottom-border-1px(rgba(7, 17, 27, 0.1))
        &:last-child
          border-none()
          margin-bottom: 0
        .icon
          flex: 0 0 57px
          margin-right: 10px
        .content
          flex: 1
          .name
            margin: 2px 0 8px 0
            height: 14px
            line-height: 14px
            font-size: 14px
            color: rgb(7, 17, 27)
          .desc, .extra
            line-height: 10px
            font-size: 10px
            color: rgb(147, 153, 159)
          .desc
            line-height: 12px
            margin-bottom: 8px
          .extra
            .count
              margin-right: 12px
          .price
            font-weight: 700
            line-height: 24px
            .now
              margin-right: 8px
              font-size: 14px
              color: rgb(240, 20, 20)
            .old
              text-decoration: line-through
              font-size: 10px
              color: rgb(147, 153, 159)
          .cartcontrol-wrapper
            position: absolute
            right: 0
            bottom: 12px
</style>
